The Mission stood east of Warren Street between 19th and 20the Ave. It was a two-story building made of hewn cottonwood logs, facing east on the plateau above the river. Its site was selected by Rev. Edward R. McKinney in 1846; building began in 1847 and was completed in 1848. It contained ten rooms and was designed to accommodate the mission, the assistants and 40 Indian pupils from the Otoe, Omaha, and Missouri tribes.